From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=80.241.56.151 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794077206; b=gH1AoFyry3ju+oAguuDi5+sZidzw+x8YgfgrJHes7TJaJmzbLvL8SMyH2RwPXY1lF1Ch oD80CsrbpakFNyeH5QPybWiUMLiPSg4xhgQkppmpp51PeI+IoATPnPSwRqTuyph44y64p zrk/z3yZddAVlZTPxcFZ22V5V+vUA9nQfxsznDeXP4xUWRCrnzQZkkP4LTRCnfDF0pvB+ O7jsnwo3eOrgjhZGKplWOLgLWZH0dGV1e5xiyCzbIHXyUqVCK9ICJNsq5q6+5q21ldfPK b1wzmITWRMJNYIoU1VzyhVhLXAqbd+sgLZXe4XnQDhBWOXQTnrVGcLckZoPNQDhQFIw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794077206; h=DMARC-Filter:Received:DKIM-Signature:Message-ID:Subject:From:To:Cc: Date:In-Reply-To:References:Content-Type:Content-Transfer-Encoding: User-Agent:MIME-Version:X-MBO-RS-META:X-MBO-RS-ID; bh=WKXSp5E4s/N1g/AjyLpdmHZ+ZbLwA33yzXCjwWw6QnM=; b=d2KrQKoLp+tf8aFS26BrayKbh8vnEc/SgaBSHp8psQ869Gr8sJYwhwS792Z3+czq1ipm 3VQKo0tTGXDU8st3z52LZovFMra5G51SYiDknh7AZhFoDYhwmdLJS97S/+xKhcCBFGo2S bP4IS7gMmoBP9R78/XUTir9W9H024zRrpaiw870Wky1Q5okFZKdrgi7JH4K5yMi8sfhtq n/tQo1YBzRTTg/mV55pcw+3JowhqT7B1c2AG8yfvsY5/kRGzGutIO72Kxi8oyh+jTzMzg 0e3/xLoKI6Eamzs5ZTu+CiY/Nk6sqp1gjEoiEGxPUNfqo/UPRdXwhsZ9Ob/41/gAAnw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=mailbox.org; spf=pass smtp.mailfrom=mailbox.org; dkim=pass header.d=mailbox.org header.i=@mailbox.org header.a=rsa-sha256 header.s=mail20150812 header.b=aSRLOajT; arc=none smtp.remote-ip=80.241.56.151 Received: from mout-p-101.mailbox.org (mout-p-101.mailbox.org [80.241.56.151]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 55515606A326 for ; Sat, 7 Nov 2026 18:46:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 55515606A326 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mailbox.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=mailbox.org header.i=@mailbox.org header.a=rsa-sha256 header.s=mail20150812 header.b=aSRLOajT Received: from smtp1.mailbox.org (smtp1.mailbox.org [IPv6:2001:67c:2050:b231:465::1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519MLKEM768 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-101.mailbox.org (Postfix) with ESMTPS id 4jMQ4d6FSzz8t17; Sat, 07 Nov 2026 19:46:41 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1794077201; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=WKXSp5E4s/N1g/AjyLpdmHZ+ZbLwA33yzXCjwWw6QnM=; b=aSRLOajTnwysnrnSlz7vzFkxh9vJ63ES6YEeLzkWJP3MO1DemEIuoyPbp9Da7H5oQzNpLG 8Z6hFswXO2+347svLGKBr15RYI6KAshDbR/klFTRwl2bwfs502vXLj/9VnC66tYCKOkJuD 39bcdHmnynC6UzcrEQG0L6ieinwDXhR5LoxapMNc3G+Ia6EeUrDsx4WYs/PIq8LqYYfQJM bjj98iJOgAZWb2NZH3naMZOWbPJGFVjc7+9ldfSIBKq0u9zgecPhz2qRC1JdQ1xP5Tqqmj pq/C0wZfflUbbmtsXpmhE2qQIxioRzICp6DvbpmGpvDnIPEHA5YqEu49JC4QNQ== Message-ID: <2208f75de73582e4d86e9f276fb3dda8751a9c56.camel@mailbox.org> Subject: Re: [PATCH v2 5/6] firmware: raspberrypi: Document memory barriers in property list path From: Manuel Ebner To: Sander Speetjens , Florian Fainelli , Broadcom internal kernel review list , Eric Anholt , Stefan Wahren , Stephen Boyd , Nicolas Saenz Julienne Cc: linux-rpi-kernel@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Date: Sat, 07 Nov 2026 19:46:38 +0100 In-Reply-To: <20261107-fix-raspberrypi-firmware-v2-5-5bfe605a5cc5@gmail.com> References: <20261107-fix-raspberrypi-firmware-v2-0-5bfe605a5cc5@gmail.com> <20261107-fix-raspberrypi-firmware-v2-5-5bfe605a5cc5@gmail.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.62.1 (3.62.1-1.fc45) X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-MBO-RS-META: q6wps7e4n8fd3gycsuy4kgwh91oenkwg X-MBO-RS-ID: ae976b0d27aad94cd80 Hi Sander, On Sat, 2026-11-07 at 19:21 +0100, Sander Speetjens wrote: > Add comments explaining the wmb() before the firmware transaction and > the rmb() before reading the response, as required by coding style. >=20 > Signed-off-by: Sander Speetjens For Patches 1-5/6: Reviewed-by: Manuel Ebner Thanks Manuel=20 > --- > =C2=A0drivers/firmware/raspberrypi.c | 2 ++ > =C2=A01 file changed, 2 insertions(+) >=20 > diff --git a/drivers/firmware/raspberrypi.c b/drivers/firmware/raspberryp= i.c > index d9a569a6dae7..57f21e4e65d6 100644 > --- a/drivers/firmware/raspberrypi.c > +++ b/drivers/firmware/raspberrypi.c > @@ -110,10 +110,12 @@ int rpi_firmware_property_list(struct rpi_firmware = *fw, > =C2=A0=09buf[1] =3D RPI_FIRMWARE_STATUS_REQUEST; > =C2=A0=09memcpy(&buf[2], data, tag_size); > =C2=A0=09buf[size / 4 - 1] =3D RPI_FIRMWARE_PROPERTY_END; > +=09/* Make sure the writes to the buffer are visible to the firmware. */ > =C2=A0=09wmb(); > =C2=A0 > =C2=A0=09ret =3D rpi_firmware_transaction(fw, MBOX_CHAN_PROPERTY, bus_add= r); > =C2=A0 > +=09/* Make sure we see the firmware's response before reading it. */ > =C2=A0=09rmb(); > =C2=A0=09memcpy(data, &buf[2], tag_size); > =C2=A0=09if (ret =3D=3D 0 && buf[1] !=3D RPI_FIRMWARE_STATUS_SUCCESS) {